I will investigate coding of spatial information by the teleost lateral line sensory system. In particular, I will study the way in which complex wave forms generated by moving objects in the water near a fish are decoded into a 3-dimensional representation of the world. Horseradish peroxidase (HRP) techniques will be used to map the anatomy of primary and secondary afferents within the brain of blind cave fish Astyanax jordanii. Neurophy siological recordings of single units will be made while objects, driven by computer control, are moved in space near the fish. Recording sites will be marked by iontophoresis of HRP, allowing reconstruction of electrode tracks. Because lateral line receptors are simple vertebrate hair cells, it is anticipated that investigation of spatial coding in this relatively simple system will contribute to an understanding of audition in particular and sensory systems in general.